Polyurethane-polyisocyanurate structural rim systems with enhanced processing

ABSTRACT

Low and high density structural RIM compositions are disclosed which have low viscosities. These compositions contain a resin &#34;B-side&#34; component which comprises a hydroxyl-functional tertiary amine polyol.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention pertains to the field of fiber-reinforcedreaction-injection-moldings. More particularly, the subject inventionpertains to reactive systems useful in preparing rigid, fiber-reinforcedpolyurethane-polyisocyanurate parts especially adapted to thetransportation and other industries. Such fiber-reinforcedreaction-injection-molded systems and the resulting parts are known asstructural-RIM or SRIM.

2. Description of the Related Art

Reaction-injection-molding (RIM) systems by now are well known to thoseskilled in the art. Commercial systems produce elastomeric productscontaining polyurethane-polyurea linkages which have many uses, forexample as automobile facias. However, such systems have relatively lowheat distortion temperatures and lack the flex modulus and tensilestrength necessary for many applications. The chemistry of thesereactive systems involves the use of a polyisocyanate "A side" (Acomponent) and a "B side" employing a mixture of compounds containingisocyanate-reactive hydrogens. These "B side" components generallyinclude one or more hydroxyl-functional polyether or polyester polyolsand one or more sterically hindered diamines. The polyol componentsreact with the isocyanate to form urethane linkages while the aminecomponents react to form urea linkages. Such systems are disclosed, forexample, in Weber U.S. Pat. No. 4,218,543.

The flex modulus and tensile strength of traditional RIM systems may beimproved through the addition of short fiber reinforcement (RRIM).However, the addition of chopped fibers raises the viscosity of thesystem components as well as seriously affecting the ease of processing.Moreover, this addition of reinforcement has little effect on matrixdominated physical properties such as heat distortion temperature (HDT).

The use of woven or non-woven (random) fiber reinforcement (StructuralRIM or SRIM) can provide parts with yet greater tensile strength andflex modulus. Furthermore, the physical properties may be madedirectional through the use of unidirectional fibers or combinations ofboth unidirectional and random fiber orientations. Unfortunately, theuse of such reinforcement has not proven practical with traditionalpolyurethane-polyurea RIM systems due to the high viscosities of suchsystems. Finally, the low heat distortion temperature of such systemscontinues to present a detriment to the use of such systems. SRIMsystems may be divided into cellular (blown) systems whose resin matrixhas a density less then 1.0 g/cm³ and whose fiber reinforced part has aflexural modulus of less than about 500,000 psi; and high densitysystems which are essentially noncellular, have resin matrix densitiesgreater than 1.0 g/cm³, and whose flexural modulus is in excess of500,000 psi.

In U.S. Pat. No. 4,035,331 are disclosed high density polyurethane RIMsystems employing a polyisocyanate, an amine-initiated polyether polyol,and a liquid modifier having a boiling point above 150° C. all in theabsence of a catalyst. The liquid modifier is present in an amount offrom 5 to 60 weight percent, preferably from 15 to 40 weight percent ofthe overall system components. Systems which contain less than about 5weight percent of modifier are said to produce unacceptable products,subject to swelling, cracking, and distortion. No mention is made of theviscosity of such systems or their suitability as SRIM systems.

In U.S. Pat. No. 4,709,002, some of the defficiencies of the '331 patentare overcome through the use of a polyisocyanate and a propylenecarbonate adduct of a tertiary amine. The products of these systems arepolyisocyanurate polymers which are suitable for use in SRIM systems.However, the alkylene carbonate tertiary amine adduct must be aged forconsiderable length of time, for example 500 hours, in order for itscatalytic activity to stabilize somewhat. As the catalytic activitycontinues to change with time, such systems are not storage stable.

It would be desirable to formulate an SRIM system capable of providing astorage stable, high heat distortion system yet having a low viscositysuitable for both low density (microcellular) and high density(non-cellular) applications without the use of large amounts of liquidmodifiers.

SUMMARY OF THE INVENTION

It has now been discovered that storage stable SRIMpolyurethane-polyisocyanurate systems having low viscosity which provideparts having high heat distortion temperature may be prepared in thesubstantial absence of liquid modifiers and yet do not crack or distort,when certain tertiary amine polyols are used as the isocyanate-reactivecomponent. Such systems may be utilized in both low density, open pourSRIM and low density and high density injection molded SRIM systems.Finally, low density systems lend themselves to use in all water-blownsystems, eliminating the use of chlorofluorocarbons, although all CFCblown systems and co-blown (CFC and water) are also feasible.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The reactive components of the subject invention SRIM systems compriseone or more polyisocyanates and an isocyanate-reactive component whichis a hydroxyl-functional tertiary amine polyether polyol. Theisocyanate-reactive component in high density SRIM systems mayoptionally include a minor amount, i.e. 4 weight percent or less basedon the total system weight, of a hydroxyl functional polyether orpolyester polyol. In low density (cellular) SRIM systems, theisocyanate-reactive component may contain up to about 50 weight percentbased on the total polyol (B-side) component of a conventional or graftpolyol and or low molecular weight chain extender. Traditionalpolyurethane-polyisocyanurate system components such as fillers, flameretardants, catalysts, blowing agents, UV stabilizers, surfactants, dyesand pigments may also be added when necessary or desirable.

Polyisocyanates which may be used as the isocyanate component includethe modified and unmodified polyisocyanates which are well known tothose skilled in the art. Unmodified polyisocyanates include aromaticand aliphatic polyisocyanates such as 2,4- and2,6-toluene-diisocyanates, 2,4-, and 2,6-methylcyclohexyldiisocyanates,1,6-hexamethylenediisocyanate, isophoronediisocyanate, 2,4'-, 4,4'-, and2,2 -diphenylmethanediisocyanates, andpolyphenylenepolymethylenepolyisocyanates. Mixtures of the aboveisocyanates as well as crude polyisocyanates, particularly less highlyrefined mixtures of the diphenylmethanediisocyanates andpolyphenylenepolymethylenepolyisocyanates (crude MDI) may be useful.

Modified polyisocyanates may also be useful, particularly thoseisocyanates which have reduced viscosity. Examples of modifiedpolyisocyanates include urethane, urea, biuret, and carbodiimidemodified polyisocyanates. Such modified polyisocyanates are well knownto those skilled in the art. Preferred isocyanates are the variousdiphenylmethanediisocyanates, their higher ring oligomers and theirmixtures. Modified diphenylmethanediisocyanates and mixtures of suchisocyanates with unmodified diphenlmethanediisocyanates and/orpolyphenylenepolymethylene polyisocyanates are also preferred.

The isocyanate-reactive component comprises one or morehydroxyl-functional tertiary amine polyether polyols. Such polyols areprepared by oxyalkylating an aliphatic or aromatic amine, preferably analiphatic amine, with an alkylene oxide. Examples of suitable aromaticamines which are useful as initiators include the variousphenylenediamines, toluenediamines, and diphenylmethanediamines.Examples of suitable aliphatic amines include ethylenediamine,propylenediamine, 1,4-butanediamine, 1,6-hexanediamine,diethylenetriamine, triethylenetetraamine and the like.Hydroxyalkylamines may also be useful, for example 2-hydroxyethylamineand 2- and 3-hydroxypropylamine, bis[2-hydroxyethyl]ethylamine,tris[2-hydroxyethyl]amine and the like. The preferred initiators are2-hydroxypropylamine and bis[2-hydroxyethyl]-2-hydroxypropylamine.

The amine or hydroxyalkylamine initiators are oxyalkylated withsufficient alkylene oxide to convert at least one and preferably allamino groups to tertiary amino groups. As alkylene oxides may bementioned ethylene oxide, propylene oxide, and butylene oxide. Mixturesof these alkylene oxides may be used, or they or their mixtures may beused sequentially to form homopolymeric, block, heteric, orblock-heteric polyether polyols. The process of preparation of suchpolyether polyols is conventional and is well known to those skilled inthe art.

Preferred hydroxyl-functional tertiary amine polyether polyols arepolyoxypropylated 2-hydroxypropylamines. Such polyols are trifunctionaland may have molecular weights from about 194 to about 2000, andhydroxyl numbers from 50 to about 600, preferably from 250 to about 600,and most preferably about 500. Polyols with lower hydroxyl numbers tendto make the polyurethane-polyisocyanurate product more flexible, usuallyat the expense of the heat distortion temperature. Lower molecularweight, higher hydroxyl number polyols are used to prepare more rigidproducts.

The flexibility of the SRIM product matrix may also be adjusted byincluding lower or higher functionality hydroxyl-functional tertiaryamine polyether polyols. For example, inclusion of polyols with afunctionality of two lowers the crosslink density thus increasingflexibility, while inclusion of polyols with functionalities of from 4to 6 or higher lead to an increase in crosslink density. In general,systems with higher crosslink densities have greater rigidity and higherheat distortion temperatures.

Useful in minor amounts are amine initiated polyether polyols which havefree amino hydrogens and hydroxyl-functional polyoxyalkylene moieties.Such polyols are prepared as taught by U.S. Pat. No. 4,517,383, byoxyalkylating an aliphatic or aromatic amine with a stoichiometricexcess of alkylene oxide, but utilizing an extraordinarily high amountof basic oxyalkylation catalyst which must be present at the onset ofoxyalkylation. Such dual-functionality assymetric polyols create bothurethane and urea linkages in the finished product, and further have theadvantage of lower viscosities than their fully oxyalkylated,symmetrical analogues.

Also useful in minor amounts, are conventional polyether polyols andacrylonitrile/styrene graft polymer polyol dispersions. Both these typesof polyols are well known items of commerce, and generally havefunctionalities from two to about eight, preferably from 2 to about 3,and hydroxyl numbers from 20 to about 600, preferably from 20 to about500. The use of such polyols increases the urethane linkages in thefinished product. Use of graft polyols may increase the flexural modulusand tensile strength. In low density SRIM systems, the minor amount ofconventional or graft polyols may be up to about half the total polyolcomponent weight. In high density SRIM systems, however, the minoramount should be less than about 4 weight percent based on the totalsystem weight.

The flexural modulus, heat distortion temperature, and rigidity of thematrix may also adjusted by varying the urethane/isocyanurate content ofthe product. The isocyanurate content is increased by increasing theratio of isocyanate (A side) to polyol (B side). In general, isocyanateindices of from 100 to about 700 are useful, preferably from 120 toabout 300, and most preferably from 150 to 250.

Hydroxyl-functional and amine-functional chain extenders may be used inboth low density and high density SRIM systems. Preferredhydroxyl-functional chain extenders are ethylene glycol, glycerine,trimethylolpropane, 1,4-butanediol, propylene glycol, dipropyleneglycol, 1,6-hexanediol, and the like. Suitable amine-functional chainextenders include the sterically hindered amines such as diethyltoluenediamine and the other hindered amines disclosed in Weber U.S. Pat. No.4,218,543. In both high and low density SRIM systems, the amount ofchain extender is generally less than 15 weight percent based on thetotal weight of the polyol component, preferably less than 10 weightpercent. In high density SRIM systems, the amount of chain extenderuseful is generally very low, i.e. less than about 4 weight percent, andlower when a conventional or graft polyol is used. Prepolymers,particularly those prepared by reacting di- or polyisocyanates withpolyester polyols may be used. Such prepolymers may desirably lower thesystem reactivity.

Plasticizers may also be used in the subject invention SRIM systems. Inlow density SRIM, the amount of plasticizer is generally less than 25weight percent of the total polyol (B-side) component. In high densitySRIM systems, generally no plasticizer is used, although very minoramounts, i.e. less than about 4 weight percent may be useful in someapplications.

Mold releases, both external and internal, may be utilized. Internalmold releases are generally mixtures of long chain carboxylate salts,particularly ammonium and substituted ammonium stearates, and calciumand zinc stearates. External mold releases are well known commercialproducts and include waxes and silicones, for example.

In low density SRIM systems, a blowing agent is necessary. Water is thepreferred blowing agent, and may be used in amounts of up to about 4weight percent of the polyol (B-side) component. The density of the foamdecreases with increasing water content. When water is used as theblowing agent, the polyisocyanate component is increasedproportionately. Calculating the amount of water required and isocyanaterequired are routinely performed by those skilled in the arts ofpolyurethane and polyisocyanurate foams.

Chlorofluorocarbons (CFC's) and other volatile organic compounds mayalso be used as blowing agents, either alone, or in conjunction withwater. When used alone, CFC blowing agents and other halogenatedorganics such as methylene chloride are generally used in amounts up toabout 30 weight percent of the polyol component, preferably from 15 toabout 25 weight percent. Other volatile organic compounds such aspentane, isopentane, acetone, and the like, are used in correspondinglylesser amounts due to their lower molecular weights. When co-blown, theCFC type blowing agents are utilized in lesser amounts, for example upto about 20 weight percent of the polyol component.

Flame retardants may also be used when required by the formulation.Suitable flame retardants are well known to those skilled in the art,but the low molecular weight halogenated phosphate esters,polyhalogenated biphenyls and biphenyloxides and the like may be usedwhen flame retardants are necessary. As the presence of such flameretardants generally causes a decrease in physical properties, use offlame retardants is not preferred.

In high density SRIM systems, a water scavenger may be useful to preventany blowing by trace amounts of water. Suitable water scavengers may besilica gels, anhydrous silica, and molecular sieves. A suitablemolecular sieve which is available commercially is Baylith® paste,available from the Mobay Chemical Company.

Ultraviolet stabilizers and absorbers may also be useful. Suchstabilizers generally act by absorbing ultraviolet radiation. Many suchultraviolet absorbers are commercially vailable, such as the Uvinul®absorbers manufactured by BASF Corporation, Parsippany, N.J.

Catalysts may also be useful, and are preferred in high density systems.Suitable catalysts include both urethane and isocyanurate reactionpromoting catalysts, and are well known to those skilled in the art ofpolyurethanes. The presence of at least an effective amount ofisocyanurate promoting catalyst is necessary. This catalyst may bepurposely added, or may be present in the polyol by neutralization ofthe alkali metal polyoxyalkylation catalyst with a carboxylic acid.Preferred urethane catalysts are amine catalysts such as those availablecommercially from Air Products Chemical Company as DABCO® X-8154 andDABCO® 33LV. Preferred trimerization (isocyanurate) catalysts are metalcarboxylates such as potassium 2-ethylhexanoate and potassium acetate.The latter is advantageously utilized as a 40 weight percent solution inethylene glycol, referred to herein as KX25. The catalysts such asdibutyltindilaurate and dibutyltindiacetate are also useful urethanecatalysts. Mixtures of amine and tin or other catalysts may be used.

When volatile organics are used as blowing agents, traditionalpolyurethane system surfactants are generally necessary. Suchsurfactants are well known to those skilled in the art. Preferredsurfactants are DC190 and DC193, silicon-containing surfactantsavailable from Dow-Corning, Midland, Mich.

Fibrous reinforcement suitable for use with SRIM is widely varied. Bothwoven and non-woven (random) reinforcement, or combinations thereof, maybe used. Suitable fibers are synthetic fibers of nylon, polyester,aramid, polyetheretherketones, polyethersulfones, polyimides, and thelike; natural fibers such as cotton, hemp, flax, jute; and mineral orceramic fibers including Wollastonite alumina, glass fibers, and carbonfibers. Preferred fibrous reinforcement due to its low cost and physicalproperties is glass fiber, either woven or nonwoven. A unique non-glassmaterial is Colback® spunbonded nonwoven comprised of a bicomponentfiber having a polyester core and polyamide skin, available from BASFCorporation, Fibers Division, Parsippany, N.J.

One or more layers of fiber reinforcement may be used depending on thedesired fiber weight. Up to 70 weight percent of the SRIM part maycomprise glass fiber reinforcement. When less dense reinforcement isutilized, the weight percent of reinforcement is generally less, forexample up to about 50 weight percent of the part.

In addition to layers of fibrous reinforcement, chopped fibers and otherfillers may be added to the isocyanate resin side of the system, thepolyol side, or both in amounts up to about 70 weight percent of theSRIM part. Both man made reinforcement such as glass fiber, carbonfiber, silicon carbide fiber, ceramics and the like may be used, ornatural reinforcement such as flaked mica, jute, cellulose fiber, amongothers.

When smooth surface finishes are required a surfacing skin or veil maybe placed in the mold prior to injection of the reactive components. Analternative method is to spray or coat the mold with a surfacing paintor coating. Smooth finishes are facilitated when tightly woven glassfabrics or highly needed random reinforcements are utilized.

In low density SRIM, the fiber reinforcement and surfacing film orfabric, if any, are laid into the mold. The mold may be shot with theintimately mixed A and B sides while open and then closed, or may beclosed and shot. The heat of reaction causes volatile blowing agents tovaporize. while water blown foams result from the reaction of water withthe isocyanate. Following a reaction time of from several seconds toseveral minutes, the part may be demolded. Generally, a mold releasecoating is necessary. Either external mold releases or internal moldreleases may be used.

In high density SRIM, the injection is under relatively high pressure,i.e. 170 bar. As no blowing agent is present, the resultant part isessentially noncellular. Mold temperature for both how density and highdensity SRIM is from 100°-180° C., preferably from 115°-150 ° F., andmost preferably about 140° F.

Preferred low density SRIM systems comprise

(A) an "A side" component comprising one or more polyisocyanates;

(B) a "B side" isocyanate reactive component, comprising

(1) 60 weight percent or more of isocyanate-reactive compounds relativeto the weight of component (B) which, based on the weight of component(1), comprises,

(a) about 50 weight percent or more of a hydroxyl-functional tertiaryamine polyol;

(b) less than about 50 weight percent of an isocyanate-reactivecomponent selected from the group consisting of

(i) convention polyoxyalkylene polyether polyols having hydroxyl numbersfrom 20 to about 600;

(ii) polyoxyalkylated amines having free amino hydrogens;

(iii) acrylonitrile/styrene graft polymer polyol dispersions;

(iv) hydroxyl-functional polyester polyols having hydroxyl numbers from20 to about 600; and

(v) mixtures thereof; and

(c) up to about 15 percent of a low molecular weight isocyanate-reactivecomponent selected from the group consisting of

(i) hydroxyl-functional chain extenders having an average functionalityof about 2 and a molecular weight of less than about 150;

(ii) hydroxyl-functional crosslinkers having an average functionalitygreater than 2 and a molecular weight of less than about 150;

(iii) sterically hindered aromatic amines having a molecular weight ofless than about 400; and

(iv) mixtures thereof; and

(2) a blowing agent selected from the group consisting of

(a) volatile organic compounds;

(b) water; and

(c) mixtures thereof;

(3) up to about 25 weight percent based on the weight of component (B)of a plasticizer;

(4) an effective amount of an isocyanurate-promoting catalyst; whereinthe isocyanate index of the system is from 100 to about 700, and whereinthe viscosity of component (B) is less than about 1000 cp, preferablyless than about 500 cp, and most preferably less than about 300 cp.

The preferred high density SRIM systems comprise

(A) an "A Side" component comprising one or more polyisocyanates;

(B) an isocyanate reactive component, comprising

(1) 85 weight percent or more of a hydroxyl-functional tertiary aminepolyol;

(2) up to about 8 weight percent, based on the weight of (B), of anisocyanate-reactive component selected from the group consisting of

(a) hydroxyl-functional polyoxyalky polyether polyols having hydroxylnumbers of from 20 to about 600;

(b) hydroxyl-functional polyester polyols having hydroxyl numbers offrom 20 to about 600;

(c) acrylonitrile/styrene graft polymer polyol dispersions;

(d) a low molecular weight isocyanate-reactive component selected fromthe group consisting of

(i) hydroxyl-functional chain extenders having an average functionalityof about 2 and a molecular weight less than about 150.

(ii) hydroxyl-functional crosslinkers having an average functionalitygreater than 2 and a molecular weight less than 150; and

(iii) mixtures thereof;

(3) up to about 14 weight percent based on the weight of (B) of asterically hindered aromatic diamine chain extender; and wherein theisocyanate index is from 100 to about 700, and wherein the viscosity ofcomponent B is less than about 500 cps. Preferably, the high densitySRIM forming composition contains no plasticizer and no reactive ornonreactive liquid diluents or modifiers.

The subject invention will now be illustrated by several examples. Inthe examples, all parts are parts by weight.

EXAMPLES 1-7 LOW AND HIGH DENSITY SRIM FORMULATIONS

Low density SRIM formulations were prepared according to Table I. InTable I, the tertiary amine polyol is an oxypropylated ethanolaminehaving a hydroxyl number of about 500 and a water content of 0.05 weightpercent maximum and a functionality of 2.98. Residual oxyalkylationcatalyst (potassium hydroxide) was neutralized with 2-ethylhexanoicacid. Catalyst A is a 40 weight percent solution of potassium acetate inethylene glycol, catalyst B is 50 weight percent solution of potassiumacetate in ethylene glycol, catalyst C is dimethylcyclohexylamine,Catalyst D is DABCO® 33LV, while Catalyst E is DABCO x-8154. PlasticizerA is Plastolein® 9214, a plasticizer supplied by Quantum ChemicalCorporation and believed to be an epoxidized fatty ester. Surfactant Ais DC190, while surfactant B is DC193, both surfactants useful informulating polyurethane foams, and which are supplied by the DowCorning Company. Polyol A is a tertiary amine based polyol polyetherpolyol having a functionality of 3 and a hydroxyl number of 500. PolyolB is Dianol 2210, a polyoxypropylene glycol supplied by Akzo, having afunctionality of 2 and a hydroxyl number of 280. Polyol C is SD490, apolyether polyol having a functionality of 4.4 and a hydroxyl number of490 supplied by Alkaril Chemicals, Ltd.

Isocyanate M10 is a polymeric isocyanate having an NCO content of 32weight percent, and a viscosity of 60 cps when measured at 25 C;isocyanate M20S is a polymeric isocyanate having an NCO content of 31.8weight percent and a viscosity of 195 cps at 25 C. Isocyanate MM103, acarbodiimide modified methylenediphenylene diisocyanate having an NCOcontent of 29.5 weight percent and a viscosity of 50 cps at 25 C, hasalso been found to work well in these systems.

Material selection exclusive of fibrous reinforcement is shown in Table1 and the parameters of use are shown in Table 2.

                                      TABLE 1                                     __________________________________________________________________________             Example                                                              Component.sup.1                                                                        1.sup.2                                                                             2.sup.3                                                                            3.sup.3                                                                             4.sup.3                                                                            5.sup.4                                        __________________________________________________________________________    Polyol A 64.4  67   37.5  36   98                                             Polyol B 4.0                                                                  Polyol C            28.1  27                                                  Plasticizer A  19   18.8  22.5                                                Glycerine                                                                              6.4   7.7  7.1   6.8                                                 Surfactant A                                                                           1.6   1.9                                                            Surfactant B        1.9   1.8                                                 Catalyst A                                                                             1.2        1.5   0.45                                                Catalyst B                     0.7                                            Catalyst C                                                                             1.6        0.8   0.45                                                Catalyst D                     0.3                                            Catalyst E                0.1                                                 Water    0.8   2.4  2.4   2.9                                                 CFC R11 B                                                                              20.0                                                                 Carbon Black                                                                           1.5   1.9  1.9   2.0                                                 Baylith.sup. ®  Paste      1.0                                                     100 wt %                                                                            100 wt %                                                                           100 wt %                                                                            100 wt %                                                                           100 wt %                                       __________________________________________________________________________     .sup.1 These components are for the resin side of the twocomponent            chemical system, resin and isocyanate                                         .sup.2 Low density SRIM coblown chemical system                               .sup.3 Low density SRIM water blown chemical system                           .sup.4 High density SRIM unblown chemical system                         

The results of physical testing of various systems at various resin/isoratios and with various reinforcements types and content are give below.

                                      TABLE 2                                     __________________________________________________________________________                   Example                                                        Property       1.sup.1                                                                            2    3    4    5                                          __________________________________________________________________________    Viscosity of Resin at 25° C., cp                                                      <100 150  1250 800  290                                        Isocyanate Used with Resin                                                                   M20S M20S M20S M20S M10                                        Viscosity of Isocyanate                                                                      195  195  195  195  60                                         at 25° C., cp                                                          Foam Free Rise Density, PCF                                                                  6.25 2.75 3.20 2.75 68.6                                       Resin/Isocyanate Ratios Used                                                                 A    A    A    A    A                                                         100/120                                                                            100/120                                                                            100/150                                                                            100/160                                                                            100/160                                                        B    B                                                                        100/150                                                                            100/170                                                                  C    C                                                                        100/180                                                                            100/180                                              __________________________________________________________________________     .sup.1 Trials A, B, C                                                    

Process conditions are shown in Table 3. For low-density SRIM chemicalsystems, the process can be considered to be one of a foam dispersedinto a reinforcement mat within an open or closed mold cavity. Initialdispersal of the system is in a period of time less than the cream timeof the material and in such a fashion that the mold is only partiallyfilled. After the inception of cream, the foam flows through thereinforcement within the closed and heated mold cavity to create orcomposite part that has no voids and has cured sufficiently to behandled after removal For the high density SRIM system, the process canbe considered to be one of closed injection of a non-foam dispersed intoa reinforcement mat under pressure and in a period of time less than thegel time of the material. In-mold paint, in-mold coatings, in-moldfabrics, and miscellaneous hardware can be placed in the mold at thetime of molding with these chemical systems. In Table 4a and 4b, thetrial designations, for example 2A-1 and 2B-4 indicate by their firstdigit the composition of the resin/isocyanate from Table 1; by A, B, orC the isocyanate index as in Table 2; and by the last digit, thenumerical trial. Thus 2B-4 is trial number 4, using the chemistry ofExample 2 from Table 1 at an isocyanate index of 150.

                  TABLE 3                                                         ______________________________________                                        Typical Process Conditions                                                    ______________________________________                                        Dispensing Machine                                                                           Elastogran Puromat 80 typ                                      Component Temperatures:                                                       A-Comp., Polyol Resin                                                                        73° F. (23° C.)                                  B-Comp., Isocyanate                                                                          73° F. (23° C.)                                  Component Impingement                                                         Mixing Pressures:                                                             A-Comp.        2200-2500 psi (150-170 bar)                                    B-Comp.        2200-2500 psi (150-170 bar)                                    Molded Temperature                                                                           140° F. (60° C.)                                 Demold time    2 minutes typ. for low-                                                       density SRIM, 1 minute typ. for                                               high-density SRIM                                              Cream time     20 seconds typ. for low-density                                               SRIM                                                           Gel time       1.6 lb typ. (726 p typ.) for                                                  high-density SRIM                                              Free rise density                                                                            2.8 lb/cu ft. typ. (004 g/cc typ.)                                            10 sec. typ. for high-density SRIM                             Short rate     0.5 lb/sec. typ. (227 g/sec typ.)                              Short size     0.8 lb typ. (353 g typ.) for                                                  low-density SRIM                                               Mold pressure  80-100 psi typ. for low-density SRIM                                          200 psi typ. for high-density SRIM                             ______________________________________                                    

                                      TABLE 4a                                    __________________________________________________________________________    Plaque* Data, Blown Chemical Systems)                                         __________________________________________________________________________                           Example:                                                                      2A-1     2A-2          2B-4    2B-5                                           OCF 8610 OCF 8610      OCF 8610                                                                              OCF 8610                                       GLASS MAT                                                                              GLASS MAT                                                                             2A-3  GLASS MAT                                                                             GLASS MAT               REINFORCEMENT  PUBLISHED                                                                             29.5 wt %                                                                              28.8 wt %                                                                             0 wt %                                                                              28.3 wt %                                                                             28.2 wt %               PROPERTY       METHOD  GLASS    GLASS   GLASS GLASS   GLASS                   __________________________________________________________________________    Thickness (in.)                                                                              FBTM 57-4                                                                             0.163    0.169   0.178 0.200   0.193                   Specific Gravity                                                                             ASTM D104                                                                             0.344    0.344   0.187 0.306   0.300                   Warpage %      FBTM 58-28                                                                            0        0       4     0       1                       Tensile Strength (PSI)                                                                       ASTM D103                                                                             2100     2100    400   1500    1900                    Flex Strength (PSI)                                                                          ASTM D790                                                                             2800     2400    400   2300    2500                    Flex Modulus (PSI)                                                                           ASTM D790                                                                             126,000  100,000 15,000                                                                              94,000  119,000                 Flammability (in/min)                                                                        MVSS 302                                                                              0.2      0.4     1.0   0.2     0.2                     Heat Distortion        190      160     140   180     170                     (°F.) (264 PSI Load)                                                   24 Hr. Water   SAE J315                                                                              3        3       8     2       2                       Absorption (%)                                                                Water Swell (%)                                                                              SAE J315                                                                              1.9      1.2     3.5   1.7     0                       Dimensional Stability                                                                        SAE J315                                                       Expansion, 70° F., 24 hrs.                                                                    0.1      0.1     0.1   0.2     0.3                     Contraction, 190° F., 24 hrs.                                                                 0.2      0.1     0.2   0.1     0.2                     Coefficient of Linear                                                                        ASTM D696                                                                             4.5 × 10.sup.-6                                                                  4.5 × 10.sup.-6                                                                 1 × 10.sup.-5                                                                 1.5 × 10.sup.-6                                                                 4.5 ×                                                                   10.sup.-6               Thermal Expansion                                                             (in./in. °F.)                                                          __________________________________________________________________________                           Example:                                                                      2B-6     2B-7    2B-8    2B-9   2B-10                                         OCF 8610 OCF 8610                                                                              COLBACK COLBACK                                                                              COLBACK                                       GLASS MAT                                                                              GLASS MAT                                                                             N80     N100   N120                   REINFORCEMENT  PUBLISHED                                                                             29.2 wt %                                                                              30.4 wt %                                                                             7.9 wt %                                                                              9.7 wt %                                                                             11.4 wt %              PROPERTY       METHOD  GLASS    GLASS   COLBACK COLBACK                                                                              COLBACK                __________________________________________________________________________    Thickness (in.)                                                                              FBTM 57-4                                                                             0.178    0.142   0.182   0.159  0.173                  Specific Gravity                                                                             ASTM D104                                                                             0.312    0.317   0.223   0.213  0.239                  Warpage %      FBTM 58-28                                                                            0        0       0       0      0                      Tensile Strength (PSI)                                                                       ASTM D103                                                                             1500     2200    600     500    600                    Flex Strength (PSI)                                                                          ASTM D790                                                                             2300     2300    600     600    600                    Flex Modulus (PSI)                                                                           ASTM D790                                                                             86,000   96,000  22,000  22,000 23,000                 Flammability (in/min)                                                                        MVSS 302                                                                              0.2      0.2     0.8     0.6    0.8                    Heat Distortion        170      180     140     140    160                    (°F.) (264 PSI Load)                                                   24 Hr. Water   SAE J315                                                                              2        2       3       4      4                      Absorption (%)                                                                Water Swell (%)                                                                              SAE J315                                                                              1.9      2.2     1.0     0.5    0.5                    Dimensional Stability                                                                        SAE J315                                                       Expansion, 70° F., 24 hrs.                                                                    0.2      0.3     0.1     0.6    0.9                    Contraction, 190° F., 24 hrs.                                                                 0.0      0.0     0.3     0.3    0.1                    Coefficient of Linear                                                                        ASTM D696                                                                             9 × 10.sup.-6                                                                    1.5 × 10.sup.-6                                                                 7.3 × 10.sup.-6                                                                 3.0 × 10.sup.-6                                                                1.5 ×                                                                   10.sup.-6              Thermal Expansion                                                             (in./in. °F.)                                                          __________________________________________________________________________                           Example:                                                                                      2B-13                                                         2B-11   2B-12   COLBACK 2B-14                                                 COLBACK COLBACK 5 × N120                                                                        COLBACK                                               2 × N80                                                                         4 × N80                                                                         1 × N80                                                                         10 × N100                                                                       2B-15                  REINFORCEMENT  PUBLISHED                                                                             14.8 wt %                                                                             23.3 wt %                                                                             33.3 wt %                                                                             42.6 wt %                                                                             0 wt %                 PROPERTY       METHOD  COLBACK COLBACK COLBACK COLBACK COLBACK                __________________________________________________________________________    Thickness (in.)                                                                              FBTM 57-4                                                                             0.184   0.165   0.183   0.184   0.151                  Specific Gravity                                                                             ASTM D104                                                                             0.242   0.300   0.503   0.524   0.203                  Warpage %      FBTM 58-28                                                                            0       0       0       0       0                      Tensile Strength (PSI)                                                                       ASTM D103                                                                             1600    1200    2400    3200    600                    Flex Strength (PSI)                                                                          ASTM D790                                                                             600     1300    2500    3200    500                    Flex Modulus (PSI)                                                                           ASTM D790                                                                             20,000  41,000  91,000  112,000 20,000                 Flammability (in/min)                                                                        MVSS 302                                                                              0.2     0.2     0.2     0.2     0.4                    Heat Distortion        160     150     160     170     150                    (°F.) (264 PSI Load)                                                   24 Hr. Water   SAE J315                                                                              3       2       1       2       3                      Absorption (%)                                                                Water Swell (%)                                                                              SAE J315                                                                              1.5     0.5     1.4     2.0     2.8                    Dimensional Stability                                                                        SAE J315                                                       Expansion, 70° F., 24 hrs.                                                                    0.8     0.5     0.6     0.3     1.0                    Contraction, 190° F., 24 hrs.                                                                 0.2     0.1     0.1     0.2     0.2                    Coefficient of Linear                                                                        ASTM D696                                                                             1.5 × 10.sup.6                                                                  6.0 × 10.sup.-6                                                                 1.5 × 10.sup.-6                                                                 4.5 × 10.sup.-6                                                                 1.5 ×                                                                   10.sup.-6              Thermal Expansion                                                             (in./in. °F.)                                                          __________________________________________________________________________                           Example:                                                                      2B-16          3A**     3B**    3C**                                          OCF 8610       OCF 8610 OCF 8610                                                                              OCF 8610                                      GLASS MAT                                                                             2C-17* GLASS MAT                                                                              GLASS MAT                                                                             GLASS MAT              REINFORCEMENT  PUBLISHED                                                                             29.0 wt %                                                                             0 wt % 31 wt %  31 wt % 31 wt %                PROPERTY       METHOD  GLASS   GLASS  GLASS    GLASS   GLASS                  __________________________________________________________________________    Thickness (in.)                                                                              FBTM 57-4                                                                             0.242   0.178  0.170    0.150   0.160                  Specific Gravity                                                                             ASTM D104                                                                             0.267   0.160  0.55     0.55    0.55                   Warpage %      FBTM 58-28                                                                            0       2      --       --      --                     Tensile Strength (PSI)                                                                       ASTM D103                                                                             1000    380    3100     3000    3200                   Flex Strength (PSI)                                                                          ASTM D790                                                                             1100    520    4900     4100    2800                   Flex Modulus (PSI)                                                                           ASTM D790                                                                             66,000  17,000 482,000  163,000 100,00                 Flammability (in/min)                                                                        MVSS 302                                                                              0.4     0.5    Self     Self    Self                                                         Extinguish                                                                             Extinguish                                                                            Extinguish             Heat Distortion        200     148    --       --      --                     (°F.) (264 PSI Load)                                                   24 Hr. Water   SAE J315                                                                              2       1.8    --       --      --                     Absorption (%)                                                                Water Swell (%)                                                                              SAE J315                                                                              2.1     6.9    --       --      --                     Dimensional Stability                                                                        SAE J315                                                       Expansion, 70° F., 24 hrs.                                                                    0.1     1.2    --       --      --                     Contraction, 190° F., 24 hrs.                                                                 0.4     0.2    --       --      --                     Coefficient of Linear                                                                        ASTM D696                                                                             9.0 × 10.sup.-6                                                                 9.1 × 10.sup.-6                                                                --       --      --                     Thermal Expansion                                                             (in./in. °F.)                                                          __________________________________________________________________________                                           Example:                                                                      4A-1**  4A-2*                                                                 OCF 8610                                                                              OCF 8610                                                                              4A-3*                                                         GLASS MAT                                                                             GLASS MAT                                                                             OCF 8610                               REINFORCEMENT  PUBLISHED                                                                             24.4 wt %                                                                             27.0 wt %                                                                             GLASS MAT                              PROPERTY       METHOD  GLASS   GLASS   31.0 wt                __________________________________________________________________________                                                           %                                      Thickness (in.)                                                                              FBTM 57-4                                                                             0.103   0.106   0.105                                  Specific Gravity                                                                             ASTM D104                                                                             0.716   0.841   0.553                                  Warpage %      FBTM 58-28                                                                            0.4     0.4     0.01                                   Tensile Strength (PSI)                                                                       ASTM D103                                                                             8700    10,400  5400                                   Flex Strength (PSI)                                                                          ASTM D790                                                                             12,000  11,000  8800                                   Flex Modulus (PSI)                                                                           ASTM D790                                                                             453,000 413,000 387,000                                Flammability (in/min)                                                                        MVSS 302                                                                              Self    Self    Self                                                          Extinguish                                                                            Extinguish                                                                            Extinguish                             Heat Distortion        --      --      --                                     (°F.) (264 PSI Load)                                                   24 Hr. Water   SAE J315                                                                              --      --      --                                     Absorption (%)                                                                Water Swell (%)                                                                              SAE J315                                                                              --      --      --                                     Dimensional Stability                                                                        SAE J315                                                       Expansion, 70° F., 24 hrs.                                                                    0.04    0.04    0.03                                   Contraction, 190° F., 24 hrs.                                                                 0.04    0.04    0.01                                   Coefficient of Linear                                                                        ASTM D696                                                                             --      --      --                                     Thermal Expansion                                                             (in./in. °F.)                                          __________________________________________________________________________     *21" × 21"-                                                             **Notched Izod Impacts 5.26-5.52 ftlb/in                                 

                                      TABLE 4b                                    __________________________________________________________________________    (Plaque* Data, Unblown Chemical Systems**)                                    __________________________________________________________________________                      Example:                                                                      5A-1    5A-2    5A-3         5A-5    5A-6                                     NICO 751                                                                              NICO 751                                                                              NICO 751     OCF 8610                                                                              OCF 8610               REINFORCE-        GLASS MAT                                                                             GLASS MAT                                                                             GLASS MAT                                                                             5A-4 GLASS MAT                                                                             GLASS MAT              MENT      PUBLISHED                                                                             15.6 wt %                                                                             25.9 wt %                                                                             34.0 wt %                                                                             0 wt %                                                                             11.3 wt %                                                                             20.1 wt %              PROPERTY  METHOD  GLASS   GLASS   GLASS   GLASS                                                                              GLASS   GLASS                  __________________________________________________________________________    Thickness (in.)   0.125   0.125   0.125   0.125                                                                              0.125   0.125                  Flex Modulus (PSI)                                                                      ASTM D790                                                                             240,000 800,000 770,000 330,000                                                                            630,000 830,000                Flex Strength (PSI)                                                                     ASTM D790                                                                             7100    21,900  20,100  9200 13,800  20,700                 Tensile Strength                                                                        ASTM D103                                                                             7600    12,300  15,900  7000 7100    10,800                 (PSI)                                                                         Izod Impact       5.5     --      10.0    0.28 4.4     5.6                    (Notched)                                                                     (ft-lb/in.)                                                                   Heat Distortion   246     312     327     190  206     315                    (°F.)                                                                  (264 PSI Load)                                                                __________________________________________________________________________                         Example:                                                                              5A-8                                                                          OCF 8610 GLASS                                                        5A-7    MAT w/COLBACK                                                                              5A-9   5A-10  5A-11                                      OCF 8610                                                                              N120 BOTH SIDES OF                                                                         COLBACK                                                                              COLBACK                                                                              COLBACK               REINFORCE-           GLASS MAT                                                                             THE GLASS MAT                                                                              N120 MAT                                                                             N120 MAT                                                                             N120 MAT              MENT         PUBLISHED                                                                             28.0 wt %                                                                             28.0 wt % GLASS                                                                            3.7 wt %                                                                             14.9 wt                                                                              26.8 wt %             PROPERTY     METHOD  GLASS   8.7 wt % COLBACK                                                                           COLBACK                                                                              COLBACK                                                                              COLBACK               __________________________________________________________________________    Thickness (in.)      0.125   0.125        0.125  0.125  0.125                 Flex Modulus (PSI)                                                                         ASTM D790                                                                             933,000 320,000      320,000                                                                              360,000                                                                              418,000               Flex Strength (PSI)                                                                        ASTM D790                                                                             24,200  9400         8500   10,000 11,200                Tensile Strength                                                                           ASTM D103                                                                             18,600  21,300       5500   6600   7500                  (PSI)                                                                         Izod Impact          8.7     8.8          0.37   2.18   3.20                  (Notched)                                                                     (ft-lb/in.)                                                                   Heat Distortion      325     321          178    196    193                   (°F.)                                                                  (264 PSI Load)                                                                __________________________________________________________________________     Unblown Density = 70 lb/ft.sup.3                                              *21" × 21"-                                                             **However, the entrainment of air may occur during the molding process   

I claim:
 1. A reactive composition suitable for preparing rigid,polyurethane-polyisocyanurate, low density structural RIM parts having adensity of less than 1.0 g/cm³, comprising:(A) an "A side" componentcomprising one or more polyisocyanates; (B) A "B side" isocyanatereactive component, comprising 60 weight percent or more relative to theweight of the (B) component of isocyanate reactive compounds, and (C) anamount of an isocyanurate promoting catalyst effective to catalyze theformation of isocyanurate linkages,wherein said reactive components (B)comprise a minimum of about 50 weight percent of a hydroxyl-functionaltertiary amine polyol wherein said hydroxyl-functional tertiary aminepolyol is prepared by oxyalkylating an initiator selected from the groupconsisting of aryl amines, aliphatic amines, and hydroxyalkylamineswherein said (B) component further comprises a blowing agent; whereinthe viscosity of said (B) component is less than about 1000 cp, andwherein the isocyanate index calculated from the (A) and (B) componentsis greater than
 100. 2. The composition of claim 1 wherein said (B)component further comprises up to 15 weight percent of anisocyanate-reactive compound selected from the group consisting of(1)hydroxyl-functional chain extenders having an average functionality ofabout 2 and a molecular weight of less than about 150; (2)hydroxyl-functional crosslinkers having an average functionality ofgreater than about 2 and a molecular weight less than about 150; (3)sterically hindered aromatic amines having a molecular weight of lessthan about 400; and (4) mixtures thereof.
 3. The composition of claim 1wherein said component (B) further comprises up to about 20 weightpercent of a plasticizer.
 4. The composition of claim 2 wherein saidcomponent (B) further comprises up to about 20 weight percent of aplasticizer.
 5. The composition of claim 1 wherein said (B) componentfurther comprises an isocyanate-reactive compound selected from thegroup consisting of(1) hydroxyl-functional polyether polyols havinghydroxyl numbers from 20 to about 600; (2) hydroxyl-functional polyesterpolyols having a hydroxyl number from 20 to about 600; (3) aminefunctional polyether polyols; (4) polyether polyols prepared byoxyalkylating an amine in such a manner that the resulting polyetherpolyol polyols contains both hydroxyl-functional polyoxyalkylene groupsand free amino hydrogens; (5) graft polymer polyether polyoldispersions; and (6) mixtures thereof.
 6. The composition of claim 2wherein said (B) component further comprises an isocyanate-reactivecompound selected from the group consisting of(1) hydroxyl-functionalpolyether polyols having hydroxyl numbers from 20 to about 600; (2)hydroxyl-functional polyester polyols having a hydroxyl number from 20to about 600; (3) amine functional polyether polyols; (4) polyetherpolyols prepared by oxyalkylating an amine in such a manner that theresulting polyether polyol polyols contains both hydroxyl-functionalpolyoxyalkylene groups and free amino hydrogens; (5) graft polymerpolyether polyol dispersions; and (6) mixtures thereof.
 7. Thecomposition of claim 3 wherein said (B) component further comprises anisocyanate-reactive compound selected from the group consisting of(1)hydroxyl-functional polyether polyols having hydroxyl numbers from 20 toabout 600; (2) hydroxyl-functional polyester polyols having a hydroxylnumber from 20 to about 600; (3) amine functional polyether polyols; (4)polyether polyols prepared by oxyalkylating an amine in such a mannerthat the resulting polyether polyol polyols contains bothhydroxyl-functional polyoxyalkylene groups and free amino hydrogens; (5)graft polymer polyether polyol dispersions; and (6) mixtures thereof. 8.The composition of claim 4 wherein said (B) component further comprisesan isocyanate-reactive compound selected from the group consisting of(1)hydroxyl-functional polyether polyols having hydroxyl numbers from 20 toabout 600; (2) hydroxyl-functional polyester polyols having a hydroxylnumber from 20 to about 600; (3) amine functional polyether polyols; (4)polyether polyols prepared by oxyalkylating an amine in such a mannerthat the resulting polyether polyol polyols contains bothhydroxyl-functional polyoxyalkylene groups and free amino hydrogens; (5)graft polymer polyether polyol dispersions; and (6) mixtures thereof. 9.A composition suitable for the preparation of rigid, high density,polyurethane-polyisocyanurate structural RIM parts having a densitygreater than 1.0 g/cm³, comprising:(A) an "A side" component comprisingone or more polyisocyanates; and (B) a "B side" isocyanate-reactioncomponent, comprising at least 85 weight percent or more of ahydroxyl-functional tertiary amine polyol wherein saidhydroxyl-functional tertiary amine polyol is prepared by oxyalkylatingan initiator selected from the group consisting of aryl amines,aliphatic amines, and hydroxyalkylamines; and (C) less than about 8weight percent based on the weight of component (B) of an isocyanatereactive component selected from the group consistingof(1)hydroxyl-functional polyether polyols having hydroxyl numbers from20 to about 600; (2)hydroxyl-functional polyester polyols having ahydroxyl number from 20 to about 600; (3)amine functional polyetherpolyols; (4)polyether polyols prepared by oxalkylating an amine in sucha manner that the resulting polyether polyol polyols contains bothhydroxyl-functional polyoxyalkylene groups and free amino hydrogens;(5)graft polymer polyether polyol dispersions; and (6)mixturesthereof,wherein the viscosity of said component (B) is less than about1000 cp, and wherein he isocyanate index calculated from the (A) and (B)components is greater than about
 100. 10. The composition of claim 9wherein said composition further comprises up to about 15 weight percentbased on component (B) of an isocyanate-reactive compound selected fromthe group consisting of(1) hydroxyl-functional chain extenders having anaverage functionality of about 2 and a molecular weight of less thanabout 150; (2) hydroxyl-functional crosslinkers having an averagefunctionality of greater than about 2 and a molecular weight less thanabout 150; (3) sterically hindered aromatic amines having a molecularweight of less than about 400; and (4) mixtures thereof.
 11. Thecomposition of claim 9 wherein said hydroxyl-functional tertiary aminepolyol has been prepared by oxyalkylating 2-hydroxyethylamine with from3 to about 20 moles of alkylene oxide.
 12. The composition of claim 10wherein said hydroxyl-functional tertiary amine polyol has been preparedby oxyalkylating 2-hydroxyethylamine with from 3 to about 20 moles ofalkylene oxide.
 13. A low density SRIM part containing fibrousreinforcement and the reaction product of the composition of claim 1.14. A high density SRIM part containing fibrous reinforcement and thereaction product of the composition of claim 9.